Three teratons of excess CO2 in the air and oceans (1 Tton of C) should be put somewhere safe and stable—living trees, wood, soil, carbon-negative cement, or—hey, how about rock? There are many carbonate minerals, and many mafic minerals that turn into stable carbonates when exposed to CO2. That includes basalts, olivines, and serpentines, including the false jade in the carving above. Also asbestos, which this process can dispose of in mine tailings, and soapstone/talc, and much more.
Various experiments have been done on various of these diverse mineral families. The process works. Now we are working on costs and efficiency.
Carbon Sequestration via Mineral Carbonation: Overview and Assessment—E&E News (Energy and Environment)
Mining costs appear to be quite low. The mining is similar to copper mining and the amount of peridotite required for a GW power plant is small compared to the amount of ore mined in a large copper mine. Cost estimates, based on other mining operations, suggest a cost of about $8 per ton of CO2.
So, for a teraton of CO2, that’s about $8 teradollars for mining.
The Project
The full cost (mining, transport, crushing, storage, disposal) is currently estimated at $18/ton. So we might be looking at $18 tbucks.
Say we do it over 40 years, so that’s $450 gigabucks annually, worldwide. Less than we are currently investing in renewable energy. Say we divide that in chunks for
- US
- Europe
- China
- India
- MENA
- Latin America
- Sub-saharan Africa
- The Rest of Asia
- Australia
and pretend that those numbers are accurate enough so that it comes to $50 billion a year for each, and it’s a serious enterprise, but entirely doable, compared with the costs of not doing it. Also, we can assume that the Fossil Fool Denialists are out of the picture after we get near Carbon Neutrality, and can discuss how to go this strongly Carbon Negative.
But, as I said, I was just pretending. Actually something like a quarter to a third of the excess CO2 could be taken up if we really do plant a trillion trees, and a comparable amount in soils if we seriously fix agriculture. So let's pretend that it comes to $25 billion in each region. Let us also pretend that we end poverty while waiting to get this project in gear, and add some tens of trillions of dollars annually to the global economy. And then we can pretend that the technology comes down in cost to a degree that we cannot yet imagine.
But here is something we don't have to pretend. All of this would cost much less than a $50/ton price on carbon. So we can talk about applying it directly to current mining operations, particularly where there are capturable CO2 streams nearby.
Renewable Monday: Pricing Carbon High Enough Works to Kill Coal
I can hear the billionaires poor-mouthing now. /s
Research
CO2 Storage Potential of Basaltic Rocks Offshore Iceland
Injection of CO2 into basaltic formations provides significant benefits including permanent storage by mineralisation and large storage volume. The largest geological storage potential lies offshore and in the case of basalt, along the mid-oceanic ridges where CO2 could be stored as carbonate minerals for thousands of years. Most of the bedrock, both on land and offshore Iceland consists of basalt that could theoretically be used for injection of CO2, fully dissolved in water. The most feasible formations are the youngest formations located within the active rift zone. It is estimated that up to 7000 GtCO2 could be stored offshore Iceland within the Exclusive Economic Zone. Site specific geological research and pilot studies are required for refining the concept and offshore pilot scale projects should be considered as the next steps in evolving the method.
In other words, 7 teratons of CO2, which is way more than enough.
The current method requires a lot of fresh water to be turned into fizzy soda and pumped into the basalt layer. Research into using saltwater is being pursued.
The original proposal for sequestering CO2 in minerals is
CO2 disposal by means of silicates
Nature volume 345, page486 (1990) (paywalled)
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488 Accesses
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368 Citations
[Abstract not available]
Accelerated carbonation technology granulation of industrial waste: Effects of mixture composition on product properties
Waste Management & Research (2020)
- Hakan Berber
- , Kadriann Tamm
- […]
- Mai Uibu
The use of accelerated carbonation technology in combination with a granulation process was employed to produce aggregates from a variety of industrial wastes, which included municipal solid waste incineration fly ash and air pollution control residue, oil shale ash, cement kiln dust, and quarry fines that have been produced in Estonia. Focusing mainly on the effects produced by the content of municipal solid waste incineration ash in the admixtures, the granule compositions were varied in order to tailor granule properties on the basis of CO2 uptake, strength development, leaching behaviour, microstructure, and morphology. All the steps involved in the accelerated carbonation technology granulation process, from mixing with additives to granulation and carbonation treatment, were carried out in the same apparatus – an Eirich EL1 intensive mixer/granulator. The amount of CO2 that was bound ranged from 23 to 108 kg per tonne of waste. The granules that included the optimised mixture of municipal solid waste incineration air pollution control residue, oil shale ash, cement kiln dust, and ordinary Portland cement were characterised by the highest compressive strength (4.03 MPa) and water durability for the size range of 4–10 mm. In addition, the process was found to be effective in reducing alkalinity (pH < 11.5) and immobilising heavy metals (especially zinc) and chloride. The composition and properties of the respective waste materials and mechanisms associated with the characteristics of the resulting granules were also addressed.
Carbonation of ophiolitic ultramafic rocks: Listvenite formation in the Late Cretaceous ophiolites of eastern Iran
Lithos (2020)
- Arman Boskabadi
- , Iain K. Pitcairn
- […]
- Reza Monazzami Bagherzadeh
Naturally carbonated minerals (Late Cretaceous ophiolitic peridotite) found in Iran.
On the controls of mineral assemblages and textures in alkaline springs, Samail Ophiolite, Oman
Chemical Geology (2020)
- Manolis Giampouras
- , Carlos J. Garrido
- […]
- Juan Manuel García-Ruiz
- Serpentinization-driven carbonation in alkaline spring systems in ophiolites
- Pool-by-pool geochemical-mineralogical-textural analysis coupled to hydrodynamics
- Assessment of CO2 uptake, evaporation, mixing as the main precipitation mechanisms
Prospects for CO2 mineralization and enhanced weathering of ultramafic mine tailings from the Baptiste nickel deposit in British Columbia, Canada
International Journal of Greenhouse Gas Control (2020)
- Ian M. Power
- , Gregory M. Dipple
- […]
- Anna L. Harrison
- The Baptiste nickel deposit is ideal for a CO2 sequestration demonstration project.
- Direct air capture of CO2 would offset ∼25% of a prospective mine’s carbon emissions.
- The Baptiste deposit could sequester CO2 from a proposed liquified natural gas pipeline.
- Reaction of CO2-rich gases with tailings would offset ∼50% of a mine’s emissions.
- Potential savings would be $10.5 M/yr under a carbon price of $50/t CO2 equivalent.
Carbon dioxide storage through mineral carbonation
Nature Reviews Earth & Environment (2020)
- Sandra Ó. Snæbjörnsdóttir
- , Bergur Sigfússon
- […]
- Eric H. Oelkers
Captured carbon can be stored through injection into reactive rocks (such as mafic or ultramafic lithologies), provoking CO2 mineralization and, thereby, permanently fixing carbon with negligible risk of return to the atmosphere. Although in situ mineralization offers a large potential volume for carbon storage in formations such as basalts and peridotites (both onshore and offshore), its large-scale implementation remains little explored beyond laboratory-based and field-based experiments. In this Review, we discuss the potential of mineral carbonation to address the global CCS challenge and contribute to long-term reductions in atmospheric CO2. Emphasis is placed on the advances in making this technology more cost-effective and in exploring the limits and global applicability of CO2 mineralization.
Google knows about lots more on this kind of thing.
This study comprises a comparative review of the effect of ball milling on the CO2 uptake of ultramafic/mafic lithologies, which are the most promising rocks for the mineralization of CO2. Samples of dunite, pyroxenite, olivine basalt and of a dolerite quarry waste material were previously subjected to ball milling to produce ultrafine powders with enhanced CO2 uptake.
The optimum milling conditions were determined through selective CO2 chemisorption followed by temperature-programmed desorption (TPD) experiments, revealing that the CO2 uptake of the studied lithologies can be substantially enhanced via mechanical activation. Here, all these data are compared, demonstrating that the behavior of each rock under the effect of ball milling
is predominantly controlled by the mineralogical composition of the starting rock materials. The ball-milled rock with the highest CO2 uptake is the dunite, followed by the olivine basalt, the pyroxenite and the dolerite. The increased CO2 uptake after ball milling is mainly attributed to the reduction of particle size to the nanoscale range, thus creating more adsorption sites per gram basis, as well as to the structural disordering of the constituent silicate minerals.
The main purpose of this exploratory project is to develop a more fundamental understanding of the long-term sequestration of CO2 via mineral carbonation reactions involving the common Mg-silicates in serpentinite and basalt mineral assemblages. Past experimental studies have shown that these reactions are kinetically limited, so we are exploring ways to enhance their kinetics, including the use of activators such as organic acids and catalysts such as natural metalloenzymes that enhance the rate of conversion of hydrated CO2 to bicarbonate ions.
This report discusses the feasibility of an alternative form of geologic CO2 storage: CO2 mineralization. In this method, CO2 reacts with rocks and minerals to form solid and stable carbonate rocks. New pilot projects and laboratory-based kinetics experiments have revealed that this method, both in situ and ex situ, may be a viable option for storage. In situ storage targets in-place rocks at the surface or subsurface. Ex situ storage targets industrial byproducts at the surface like mine tailings.
Geologists Map Rocks to Soak CO2 From Air
Mar 5, 2009 - Ultramafic rocks potentially could absorb CO2. ... Originating deep in the earth, these rocks contain minerals that react naturally with carbon dioxide to form solid minerals. Earth Institute scientists are experimenting with ways to speed this natural process, called mineral carbonation.
Ultramafic rock - Wikipedia
Ultramafic rocks are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are composed of usually greater than 90% mafic minerals.
Carbon Mineralization of CO2
Negative Emissions Technologies and Reliable Sequestration: A Research Agenda
To achieve goals for climate and economic growth, “negative emissions technologies” (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions.
In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and “sustainable scale potential” for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact.
Rapid solubility and mineral storage of CO2 in basalt —Science Direct
The long-term security of geologic carbon storage is critical to its success and public acceptance. Much of the security risk associated with geological carbon storage stems from its buoyancy. Gaseous and supercritical CO2 are less dense than formation waters, providing a driving force for it to escape back to the surface.
This buoyancy can be eliminated by the dissolution of CO2 into water prior to, or during its injection into the subsurface. The dissolution makes it possible to inject into fractured rocks and further enhance mineral storage of CO2 especially if injected into silicate rocks rich in divalent metal cations such as basalts and ultra-mafic rocks.
We have demonstrated the dissolution of CO2 into water during its injection into basalt leading to its geologic solubility storage in less than five minutes and potential geologic mineral storage within few years after injection [1], [2], [3]. The storage potential of CO2 within basaltic rocks is enormous. All the carbon released from burning of all fossil fuel on Earth, 5000 GtC, can theoretically be stored in basaltic rocks [4].
Experimental evaluation of in situ CO2‐water‐rock reactions during CO2 injection in basaltic rocks: Implications for geological CO2 sequestration
Deep aquifers are potential long‐term storage sites for anthropogenic CO2 emissions. The retention time and environmental safety of the injected CO2 depend on geologic and physical factors and on the chemical reactions between the CO2, the aquifer water, and the host rocks. The pH buffer capacity of the aquifer water and the acid neutralization potential of the host rocks are important factors for the permanent stabilization of the injected CO2. Mafic rocks, such as basalt, which primarily consists of Ca, Mg silicate minerals, have a high acid neutralization capacity by providing alkaline earth elements that form stable carbonate minerals. The carbonate minerals formed thus sequester CO2 in a chemically stable and environmentally benign form. In this study, we present results from a small‐scale CO2 injection test in mafic and metasedimentary rocks.
Assessment of carbon dioxide sequestration potential of ultramafic rocks in the greenstone belts of southern India - jstor
Regardless of the specific mix of approaches, it will be essential to permanently sequester about 10 billion tons of CO2 per year by mid-century, and roughly twice that amount each year by 2100. Maximizing the potential of technologies for CO2 removal from air and CO2 storage will help to meet global climate goals.
The research agenda published by National Academies of Sciences Engineering Medicine (2019) calls for roughly $1 billion over a 10–20 years time period to advance the deployment of CO2 sequestration in deep sedimentary reservoirs at the GtCO2/yr scale and develop CO2 mineralization at the MtCO2/yr scale. This would lead to a deeper understanding of the reservoir characteristics from the nano- to kilometer scale, some of which may include the distribution of the reaction products, the reaction rate of the minerals, the permeability evolution, the pressure build-up in the reservoir, the large-scale impact of chemicophysical processes leading to clogging or cracking, the effects of potential geochemical contamination, etc.
A Senior Essay presented to the faculty of the Department of Geology and Geophysics, Yale University, in partial fulfillment of the Bachelor's Degree.
We develop a simple model to study the drawdown of CO2 through mineral carbonation, and understand some of the conditions affecting the potential for mineral carbonation. We choose the hypothetical example of CO2 drawdown matching current global emissions for the next 50 years and estimate the volume of peridotite needed, exploring a wide range of reaction conditions. We investigate the additional volume required to account for several limiting factors over time: armoring, reservoir clogging and seismic triggering. Our calculations find that variations in the adjustable parameters significantly affect the aforementioned limiting factors, and thus also the required rock volume. The “ideal” drawdown scenario of fast reaction rate and small grains requires a peridotite volume small enough for the Semail ophiolite in Oman to theoretically draw down all the CO2.
Other Geoengineering News
West Antarctic ice collapse may be prevented by snowing ocean water onto it
A team of researchers from the Potsdam Institute for Climate Impact Research (PIK) is now scrutinising a daring way of stabilising the ice sheet: Generating trillions of tons of additional snowfall by pumping ocean water onto the glaciers and distributing it with snow canons. This would mean unprecedented engineering efforts and a substantial environmental hazard in one of the world's last pristine regions—to prevent long-term sea level rise for some of the world's most densely populated areas along coastlines from the US to China.